A quantum dynamical comparison of the electronic couplings derived from quantum electrodynamics and Förster theory:Application to 2D molecular aggregates

Frost, James E and Jones, Garth A (2014) A quantum dynamical comparison of the electronic couplings derived from quantum electrodynamics and Förster theory:Application to 2D molecular aggregates. New Journal of Physics, 16 (11). ISSN 1367-2630

[img] PDF (Frost_2014_NewJPhys) - Published Version
Download (3MB)

Abstract

The objective of this study is to investigate under what circumstances Förster theory of electronic (resonance) energy transfer breaks down in molecular aggregates. This is achieved by simulating the dynamics of exciton diffusion, on the femtosecond timescale, in molecular aggregates using the Liouville–von Neumann equation of motion. Specifically the focus of this work is the investigation of both spatial and temporal deviations between exciton dynamics driven by electronic couplings calculated from Förster theory and those calculated from quantum electrodynamics. The quantum electrodynamics (QED) derived couplings contain medium- and far-zone terms that do not exist in Förster theory. The results of the simulations indicate that Förster coupling is valid when the dipole centres are within a few nanometres of one another. However, as the distance between the dipole centres increases from 2 nm to 10 nm, the intermediate- and far-zone coupling terms play non-negligible roles and Förster theory begins to break down. Interestingly, the simulations illustrate how contributions to the exciton dynamics from the intermediate- and far-zone coupling terms of QED are quickly washed-out by the near-zone mechanism of Förster theory for lattices comprising closely packed molecules. On the other hand, in the case of sparsely packed arrays, the exciton dynamics resulting from the different theories diverge within the 100 fs lifetime of the trajectories. These results could have implications for the application of spectroscopic ruler techniques as well as design principles relating to energy harvesting materials.

Item Type: Article
Additional Information: Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Faculty \ School: Faculty of Science > School of Chemistry
Faculty of Science
Depositing User: Pure Connector
Date Deposited: 19 Feb 2015 10:06
Last Modified: 21 Apr 2020 23:53
URI: https://ueaeprints.uea.ac.uk/id/eprint/52350
DOI: 10.1088/1367-2630/16/11/113067

Actions (login required)

View Item View Item